This is a Phase II proposal to continue the development of the Genetic Analysis Package (GAP), a comprehensive computer software package for the management, simulation, and analysis using Gibbs sampling of pedigree data. The data management component of GAP will provide researchers with a convenient tool for viewing, editing, and printing their pedigrees and associated data. The simulation component is designed to generate pedigree data under a wide range of family structures, models, and ascertainment schemes. The analysis component will include all of the following: combined segregation and linkage analysis, inclusion of environmental covariates and gene-environment interactions, adjustment for censored age of disease onset, correction for several ascertainment schemes, allowance of missing data, estimation of allele frequencies, linkage to a locus with multiple alleles, and linkage to multiple loci. In addition to comprehensive data analysis capabilities, the user will enjoy a convenient, menu-driven interface between the management, simulation, and analysis components of the package. The Genetic Analysis Package will fill a void in the currently available array of programs for the analysis of pedigree data.